Effect of Grout Curtain on the Seepage Characteristics of Earth Dam by FEM

Abstract

Grouting is one of the most effective methods for controlling seepage through earth dam. Grouting reduces the flow rate of water through pores. In this study, the grout curtain is used to investigate its response to control the seepages through earth dam. Grout curtains are designated as an impervious barrier that normally exists within the dam for decreasing the seepage of water. To perform the analysis by Finite Element Method (FEM), a subprogram of Geo studio, SEEP/W, has been used. Earth dams with pervious and impervious base have been considered and grout curtain has been incorporated into it. To model the grout curtain, bentonite is considered as the grouting material. For all cases, silty clay is used in the dam body while silty clay is used for the pervious base and clay is used for the impervious base. From the numerical study, it is observed that the grout curtain is an effective measure to control the seepage through earth dam. Pore water pressure, flow velocity and gradient reduce significantly for the application of grout curtain, particularly for earth dam with impervious base. The use of grout curtain in the upstream face of the dam body together with the impervious base is sufficient to control the seepage.